If it remains localized to your overflow, and is not extremely noticeable while viewing the tank from the front, leave it IMO (or as much as possible). That hair algae is consuming loads of nitrates and phosphates even before it enters your sump. Any strands that happen to go loose will get caught in through the filtration in the sump. I personally don't see hair algae as being a terrible thing, and is actually a great thing if you can have it localized in specific areas out of the view of people looking at the tank. _________ Kibbles and bits and bits and bites, and bacon and bits and kibbles and bits...... NOT reef safe  | 
